• 정보학연구
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• 제9권4호
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• pp.75-85
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• 2006

This study is to test the influence of stock option granting information on the firm's performance. The important issue in stock option is that agent cost is the important determinant factor for the long term performance. The agent cost arises between the manager and shareholders. So many study are concentrated in diminishing the agent cost, and develop some substitute tools to measure the agent cost. The event study about stock option analyzes returns around event date at a time. Event study provides estimation periods and cumulative returns. Announcements about stock option are generally associated with positive abnormal returns in short term period, but not showing positive effect in long term period. It is important to investigate the responses of stocks to new information contained in the announcements of stock option. Therefore it is important to study the long term performance in the case of stock option. The event time portfolio approach exists the CAR model, BHAR model and WR model. And the calendar time portfolio approach has the 3 factor model, 4 factor model, CTAR model, and RATS model. This study is forced to develop and arrange two approach method in evaluating the performance, the event time portfolio approach and calendar time portfolio approach.

• 전기학회논문지
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• 제62권5호
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• pp.591-595
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• 2013

This paper presents a method of generation rescheduling using Newton's Approach which searches the solution of the Lagrangian function. The generation fuel cost and $CO_2$ emission cost functions are used as objective function to reallocate power generation while satisfying several equality and inequality constraints. The Pareto optimum in the fuel cost and emission objectives has a number of non-dominated solutions. The economic effects are analyzed under several different conditions, and $CO_2$ emission reductions offered by the use of storage are considered. The proposed approach can explore more efficient and noninferior solutions of a Multiobjective optimization problem. The method proposed is applied to a 4-machine 6-buses system to demonstrate its effectiveness.

• 시스템엔지니어링학술지
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• 제2권1호
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• pp.18-23
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• 2006

The purpose of this study and report is to provide, to the MND, an independent cost analysis of modernizing software of F-16 fighter fleets to support the use of several weapon system options, including JDAM, AIM-9X and HARM Targeting System etc. The study analyzed each options with software sizing, software cost, enabling hardware cost, flight test cost, system engineering cost, and 3 strategies. And the study proposed and analyzed some alternative strategies: strategy1 is to modernize software only within existing electronic processing capability; strategy2 is a full upgrade of weapons avionics with plug compatible electronics; strategy3 is an approach defined to mirror the USAF Common Configuration Implementation Approach (CCIP). The recommended alternative is strategy2.

• 산업경영시스템학회지
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• 제39권4호
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• pp.7-14
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• 2016

Unlike most researches that focus on single manufacturer or single buyer, this research studies the cooperation policy for two participants of supply chain such as single vendor and single buyer. Especially, this paper deals with single vendor-single buyer integrated-production inventory problem. If the buyer orders products, then the vendor will start to make products and then the products will be shipped from the vendor to the buyer many times. The buyer is supposed to order again when the buyer's inventory level hits reorder point during the last shipment and this cycle keeps repeated. The buyer uses continuous review inventory policy and customer's demand is assumed to be probabilistic. The contribution of this paper is to present a mixed approach and derive its cost function. The existing policy assumes that the size of shipping batch from single vendor to single buyer is increasing, called Type 1, or constant, called Type 2. In mixed approach, the size of shipping batch is increasing at the beginning part of the cycle, and then its size is constant at the ending part of the cycle. The number of shipping for Type 1 and Type 2 in a cycle in mixed approach is determined to minimize total cost. The relationship between parameters, for example, the holding cost per product, the set up cost per order, and the shortage cost per item and decision variables such as order quantity, safety factor, the number of shipments, and shipment increasing factor is figured out via sensitivity analysis. Finally, it is statistically proved that the mixed approach is superior to the existing approaches.

• 전기학회논문지
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• 제59권4호
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• pp.679-685
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• 2010

As the electrical power industry is restructured, the electrical power exchange is becoming extended. One of the key information used to determine how much power can be transferred through the network is known as available transfer capability (ATC). To calculate ATC, traditional deterministic approach is based on the severest case, but the approach has the complexity of procedure. Therefore, novel approach for ATC calculation is proposed using cost-optimization method, well-being method and risk-benefit method in this paper. This paper proposes the optimal transfer capability of HVDC system between mainland and a separated island in Korea through these three methods. These methods will consider production cost, wheeling charge through HVDC system and outage cost with one depth (N-1 contingency).

• Journal of the Korean Data and Information Science Society
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• 제17권3호
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• pp.743-752
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• 2006

This paper considers a Bayesian approach to replacement policy model with minimal repair. We use the criterion based on the expected cost and the expected downtime to determine the optimal replacement period. To do so, we obtain the expected cost rate per unit time and the expected downtime per unit time, respectively. When the failure time is Weibull distribution with uncertain parameters, a Bayesian approach is established to formally express and update the uncertain parameters for determining an optimal maintenance policy. Especially, the overall value function suggested by Jiagn and Ji(2002) is applied to obtain the optimal replacement period. The numerical examples are presented for illustrative purpose.

• 품질경영학회지
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• 제42권1호
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• pp.1-14
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• 2014

Purpose: In this paper, the minimal repair-replacement warranty policy is used to carry out a warranty cost analysis with warranty servicing times and failure times that are statistically correlated to bivariate distributions. Methods: Based on the developed approach by Park and Pham (2012a), we investigate the property of the Freund's bivariate exponential distribution and obtain the number of warranty services using the field data to conduct the warranty cost analysis. Results: Maximum likelihood estimates are presented to estimate the parameters and the warranty model is investigated using a Freund's bivariate exponential distribution. A numerical example is discussed to deal with the applicability of the developed approach in the paper. Conclusion: A novel approach of analyzing the warranty cost is proposed for a product in which failure times and warranty servicing times are used simultaneously to investigate the eligibility of a warranty claim.

• 동력기계공학회지
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• 제2권3호
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• pp.60-67
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• 1998

Edge detection is the first step and very important step in image analysis. We cast edge detection as a problem in cost minimization. This is achieved by the formulation of a cost function that evaluates the quality of edge configurations. The cost function can be used as a basis for comparing the performances of different detectors. This cost function is made of desirable characteristics of edges such as thickness, continuity, length, region dissimilarity. And we use a simulated annealing algorithm for minimum of cost function. Simulated annealing are a class of adaptive search techniques that have been intensively studied in recent years. We present five strategies for generating candidate states. Experimental results(building image and test image) which verify the usefulness of our simulated annealing approach to edge detection are better than other operator.

• Journal of Preventive Medicine and Public Health
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• 제39권6호
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• pp.499-504
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• 2006

Objectives : The aim of the study was to estimate the annual socioeconomic cost of diseases in Korea. Methods : We estimate both the direct and indirect costs of diseases in Korea during 2003 using a prevalence-based approach. The direct cost estimates included medical expenditures, traffic costs and caregiver's cost, and the indirect costs, representing the loss of production, included lost workdays due to illness and lost earnings due to premature death, which were estimated based on the human capital theory. The cost estimates were reported at three different discount rates (0, 3 and 5%). Results : The cost of diseases in Korea during 2003 was 38.4 trillion won based on 0% discount rate. This estimate represents approximately 5.3% of GDP The direct and indirect costs were estimated to be 22.5 trillion (58.5% of total cost) and 15.9 trillion won (41.5%), respectively. It was also found that the cost for those aged $40\sim49$ accounted for the largest proportion (21.7%) in relation to age groups. The cost of diseases for males was 23.5% higher than that for females. For major diseases, the total socioeconomic costs were 16.0, 13.4, 11.3 and 11.19% for neoplasms, and diseases of the digestive, respiratory and circulatory systems, respectively. Conclusions : This study can be expected to provide valuable information for determining intervention and funding priorities, and for planning health policies.

• 대한가정학회지
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• 제29권2호
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• pp.121-134
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• 1991

The farm housewive's labor has not been properly evaluated, although it has traditionally shared and devoted a substantial portion of the farm household economy. The objective of this study is to estimate the money value of rural women's labor. The data were got from the result of time analysis of farm housewives in 1988. Among the four estimation methods used in this study, the mixed approach of houskeeper replacement cost with individual function cost showed the greatest value in the decision criteria of different farming region, farming size, housewive's age, family size and children number. The opportunity cost approach showed the lowest value, however, is considered as the most appropriate estimation approach in rural situation in this study. It is expected that the appropriate estimation approach should be estimate the money value of rural housewive's labor and their economic position.